Both complete disjunction and complete connection leave wāw out. In disjunction the second clause has a distinct function or lacks a suitable semantic link; in connection it reiterates, strengthens or closely unpacks the first clause.
Therefore absence of wāw alone does not identify the rhetorical category. One must ask whether the propositions stand apart or whether one reinforces the communicative effect of the other.
AspectComplete disjunctionComplete connection
RelationshipSeparate or unrelatedClosely identified
Reason for faṣlAvoid false linkageAvoid artificial independence
ResultDistinct intentReinforced meaning